Method of producing modified urea aldehyde resin



Patented May 1, 1945 BIETHOD F PRODU ALD Falk a Company, Carnegie, 2a., a corporation of Pennsylvania CIN G MODIFIED UREA EHYDE RESIN Samuel s. Gutkin, Brooklyn, N. y, assignor to No Drawing. Application August 14, 1943, I Serial No. 498,727 1 8 Claims. ((2. 260-42) This invention relates to a specialized resinous urea-aldehyde alkyd product, and relates more particularly to urea-aldehyde alkyd products the specific properties of which are determined by a specialized modification in the series of steps by which the resinous product is made.

The application herein is s. continuation-inpart of my application Serial No. 192,587, filed February 25, 1938 (issued April 14, 1942, as Patent No. 2,279,312), and of my co-pending application Serial No. 435,640, filed March 21, 1942.

A primary object of my invention, as in the patent and application above noted, is so to link the alkyd reactions to a urea-aldehyde condensate of the infusible or full heat-hardening type that there is obtained a resin possessing certain inherent properties of urea-aldehyde resins of that sort, such as the properties of hardness,

gloss, fiow and color stability, coupled in measure with alkyd properties of flexibility, durability and susceptibility to modification; by so conducting the process in which the resin is produced that fusibility or solubility is retained in the reaction mass, or batch, during the forma tion of the resin without impairing in the product those characteristics of a heat-hardening urea-aldehyde resin which have been above noted.

The further and more specific object of my invention, and the feature in which the resin which is the subject matter hereof differs from the resin specifically claimed in'my above noted patent, is to utilize as a modifying component carboxylic acids, or a mixture of such acids. By the term aromatic monocarboxylic acids as herein used, I intend primarily to distinguish from the fatty oil acids, all of which are straight chain acids having more than 10 carbon atoms; and also to distinguish from the lower acyclic monocarboxylic acids having no more than '10 carbon atoms in their non-nuclear group, that is in the group, or structure, attached to the carboxyl of the acid.

The resinous products made in accordance with my invention differ from those disclosed in my above identified patent by being as a class somewhat softer and more soluble than those other products and by having greater adhesiveness. They differ slightly in detail from each other, but have in common the properties of film-formation, adhesion and strength. All are homogeneous products in that they exhibit no inherent tendency toward separation after their formation.

Generally stated, my invention includes the initial formation of a. urea-aldehyde condensation product which would be, if unmodified, heathardening and infusible, and includes the involvement of that initial condensate in reactions and modifications conducted with such determinative and modifying reagents, and under such conditions that the fusibility and solubility of the reaction batch is maintained throughout the process, and in measure is retained in the final product while also retaining in the product fundamental characteristics of the infusible urea-aldehyde condensates. This I do by effectively reacting the fundamentally infusible urea-aldehyde condensate with an unmodified polyhydric alcohol and then with a polybasic carboxylic acid, without destroying the above noted desirable properties inherent in the infusible urea-aldehyde resins. Following this, I modify the resultant resinous product by condensation and partial esterification with a cyclic monocarboxylic acid.

As typical examples of aldehyde which may be reacted with urea to give the urea-aldehyde condensate, I may name acetaldehyde, butyraldehyde, propylaldehyde, crotonaldehyde, and formaldehyde. As typical examples of unmodified polyhydric alcohols usable in my process, I may give glycerine, triethylene glycol, diethylene glycol, pentaerythritol and sorbitol. As typical of polybasic carboxylic acids which may be used, I

included in the resin one of the aromatic mono- Example No. 1

A mixture was made of parts by Weight ofurea and 300 parts by weight of commercial (40%) formaldehyde. The mixture was allowed to stand at normal room temperatureuntil an opaque resinous mass formed; It may be here noted that in the satisfactory conduct of my process, as'in this and following examples, the temperature at which the urea.

sate. This mass was heated to a temperature.

adequate to drive oil? water and to fuse the polybasic carboxylic acid which is added in this stage of the process, care being taken that the temperature of the batch does not greatly exceed 320' 1". in order to insure against decomposition in the batch, pending the next stage of the process. The polybasic carboxylic acid, which in this example specifically was phthalic anhydride, was added in a quantity of 148 parts by weight, and the batch was held at such moderately elevated temperature until capable of forming a clear bead.

It is to be understood, for this example and for succeeding examples, that the polybasic carboiwlic acid'may be added before or during temperature elevation, or may be added after the homogeneous mass of condensate and polyhydric alcohol has been brought to the maximum temperature desired. It is necessary merely that the polyhydric alcohol be added early in the process so that a homogeneous mass of the condensate and the polyhydric alcohol is formed for reaction with polybasic carboxylic acid. It will be notedthat in eii'ecting partial esteriflcation oi the condensate, I use an unmodified polyhydric alcohol; that the polyhydric alcohol is in excess of the polybasic carboxylic acid; and that both of them are in excess of the condensate. The immediate result is the maintenance of iusibility and solubility in the batch so that esterification is eflected without the use of a solubilizing agent such as a resin or solubilizing acid with the polyhydric alcohol. The final result is that I obtain a product in which the valuable properties of a heat-hardening resin have not been sacrificed to the maintenance oi solubility during its formation.

To make modification in the resinous material formed as above with partial esteriilcation ofthe condensate by reaction with the phthalic anhydride, heating of the material at moderately elevated temperature was continued. Without permitting the material to gel, I added 73 parts by weight of benzoic acid with heating from the maximum temperature of the stage next preceding to a temperature slightly above 400? F. With benzoic acid, as with all the aromatic monocarboxylic acids, a temperature of about 400 1''. was adequate to incorporate the monocarboxylic acid in the reaction batch without clouding. The batch may, if desired, be brought to a temperature substantially above 400 F. if care be taken to discontinue heating when the first signs of gelation appear in the batch.

The product was a thick viscous, semi-solid, resinous material which was clear when warm and slightly cloudy when cold. It is indicated for use in adhesives, as a plasticizer for nitrocellulose, and when extended with suitable solvent, such as the aromatic hydrocarbon solvents. ester solvents. alcohols, ketones, catalytic solvents or mixtures of such solvents, is useful as a varnish coating. i

As a variation under this same example, it may be noted that I have added as much as 100 parts Example No. 2

The procedure of this example was identical with that oi Example No. 1 and the materials used were identical with the materials oi that example, except that 98 parts by weight of maleic anhydride were used to replace the 148 parts by weightot phthalic anhydride used in Example Example No. 3

The procedure of this example was identical with that of Example No. 1 and the materials used were identical with those oi that example, except that 116 parts by weight 01 Marie acid were used instead of 148 parts by weight of phthalic anhydride used in Example No. 1.

(all

It should be noted that examples paralleling Examples Nos. 2 and 3 are not hereinafter given in conjunction with the use of other variable compounds within the bounds of my invention as herein broadly disclosed. It is, however, to be understood that in every subsequent example in which the use of phthalic anhydride is indicated, an approximately equivalent molar content of maleic anhydride, fumaric acid. or other polybasic carboxylic acid, may be used equivalently to the phthalic anhydride as the polybaslc carboxylic acid component of my resin, the procedure in each instance being identical with that described when phthalic anhydride is used. I have observed only slight difi'erence between the products in which phthalic anhydride was used as the polybasic carboxylic acid and those products in which some other polybasie. carboxylic acid was used.

Example No. 4

In this example the procedure and materials of Example No. 1 were duplicated down to the final stage, in which stage salicylic acid was used as the aromatic monocarboxylic acid in place of the benzoic acid added in Example No. l. 76 parts by weight of the salicyclic acid were added in small increments while raising the temperature of the reaction mass, or batch, from the maximum temperature of the next preceding stage of the process to a temperature in the neighborhood of 400 F. At such temperature all of the salicylic acid went into the batch with less clouding than. the benzoic acid to give when cooled a clearer, solid resinous product of light pink color. It may be noted that, the addition of salicylic acid in this stage of the process gives a product having a viscosity slightly less than that obtained when benzoic acid is used and of a particularly pale color.

Example No. 5

In this example the procedure and materials oi Example No. 1 were duplicated down to the final stage, in which stage 50 parts by weight of cinnamic acid were used as the cyclic monocarboxylic acid in place of the benzoic acid added in Example No. 1. The 50 parts by weight of asnsu 3 thecinnamieacidwereaddedinsmallinereoiureaandssopartsbyweightoierotonaldehide. Thismixture'washeatedgentlyonasteam man, or batch, iron the maximum tam bath until an opaque resinous condensate was peratmeoi'thenextprecedingstageoitheproe formed; meta-temperature slightlyabovetoill ii l Toaopartsbyweightoithecondensate'iormed suchtempsntmealloithecinnamicacidquiehiy asabove,-I added lilpartsbyweightoihish-' went into-the batch with the formation oi a test glycerine. which-loaned a-homogeneous slight cioudto givewhen oooleda-siightly opaque mass with the urea-erotonaldehyde condensate. resinousproduetoiyellowcolorationsimilarto Thismasswasheatedtoatemperatureapproachthatobtainedwithbsnaoicacid. l ing300l".untilwaterwasdrivenoR.i48parts 1 1m 3 hyweight'ot the rime anhydridebeingadded.

Example No. i were duplicated down to the M. in which stage 82 parts by weight of antbranilic acid were used as the monocarboxacid quickly went into the batch togive when cooled in, semi-solid resinous product of a light mustard color.

I Example No. .7

material.

Example 'No. a

A mixture was made of 120 grams of urea and 185 grams of commercial acetaldehyde. approxi mately 100% pure. 200 cc. of water was added while the mixture was allowed to stand at normalroom temperature until an opaque resinous mass formed.

To 50 grams of the condensate thus formed there was added 154 grams of high-test glycerine which formed a homogeneous mass with the ureaacetaldehyde condensate. This mass was heated to a temperature approaching 300 F. until water was driven oil, and at that temperature 148 grams oi phthalic anhydride was added and the batch was held until capable of forming a clear head.

I then added 73 grams of benzoic acid and heated the batch to a temperature slightly above The product was a dark. viscous material wh ch cooled to an extremely viscous semi-solid resinone material. It appears particularly suitable for use as a plasticizer and. as an ingredient of colloidal dispersions usable as coating compositions.

The procedure and materials of Example No. 9 were duplcated down to the final modification, in which stage I added in one instance salicylic acid, and in another instance cinnamic.

acid.' In both'instances there was only slight diflerence in the product from the productobtained in Example No. 8.

Example No. 9 v A mixture was made of 120 parts by weight The batch was held at that temperature until capable of forming a clear head.

Ithenadded'npartsbyweightolbenaoic acid and continued heating to a temperature slightly above 400' I.

The product when cooled was a very viscous. semi-solid material which was a reddish-brown in color. It was slightly opaque.

The procedure and materials of Example No. 9 were duplicated down to the last addition. in which stage I added in one instance salicylic acid, and in another instance cinnamic acid. In both instances there was only slight 'diilference in the product from the product obtained in Example Sample No. 10

Example No. 11

To 100 parts by weight of the resinous product made inaccordance with Example No. 4, I added 100 parts by weight of linseed oil, the temperature of the resinous product beingmaintained at about 430? 1. while the linseed oil was very slowly added. The product was a coating material having by virtue of its resin content exceptional capacity to acquire gloss and hardness in a dim.

Example No. 12

To 100 parts by weight of the resinous product obtained from the procedure of Example No. 9, I added 100 parts by weight of linseed oil, the temperature of the resinous product being maintained at about 430 F. while the linseed oil was very slowly added. The product was a coating material having by virtue of its resinous content exceptionalcapacity to acquire gloss and hardness in a The procedure of Examples Nos. 10, 11 and 12 was duplicated, adding, however, 100 parts by weight of soya bean oil in place of the linseed oil added in those examples.

All the several resinous products obtained by practicing my method have good solubility in the solvents which are above noted. As the content of monocarboxylic acid in the final product is increased, thefviscosity of the product is decreased and the solubility of the product correspondingly increases to the extent that in many instances solubility in mineralspirits is obtained. Although I use an initial condensate inherently possessing full heat-hardening properties, by using an unmodified polyhydric alcohol, by causing that alcohol to 'solubilize the initial condensate, and without the use of added solubilizing a ents, I- am able to maintain the reaction mass, or batch,

in" issu which permits one take by the avoidance of high temperature in the batch prior tothe addition monocarboxylic' acid-in the final stage, the batch being still in solubilined condition by virtue of the use of'an polyhydric alcohol and the conditions of its'usc. I enabled to stantial additionsof licjacids of the sort to 'which this present invention relates. As

above noted, thequantity of such acids [which added is not critical. a In distinction from my issued tent, to-whieh reference-has been above medal-utilize asthe I monoc'arboxylic modifying ingredient of my resin cyclic monocarboxylic acids instead oi the fatty oil acids. '1 have herein noted a number of the cyclic monocarboxylic acids, and have exemplified several of them. The employment of I various polybasic carboxylic acidsin making alkyd modification in urea-aldehyde resin having been'fully developed in the art, I have noted specincally herein but-tour of that class. namely phthalic anhydride, maleic anhydride, malic acid and fumaric acid. It is to be understood, however, that any other polybasic carboxylicacid which the art has found to be suitable for the alkyd modiilcation of urea-aldehyde resin. may

be employed while conforming to theprinciples of' my invention and following the procedure of my method as outlined in the examples above given. I have also given as examples of polyhydric alcohols other than .glycerine, pentaerythritol, triethylene glycol, diethylene g ycol, and sorbitol.v

When used as equivalents for glycerine. these alcohols are used in quantities of approximate molar equivalency with the g ycerine specifically exemplified herein. This is also true of aldehydes such .as butyraldelrvde, which have not speciilcallybeenexemplifiedherein.

It may be emphasized that the result of my method is to give a resin suitablelfor various uses.

and which is particularly adapted for use in hard varnish films, and in adhesives; in which the initial condensate is a or full heat-hardening properties, and ln'which'the advantageous features attendant upon those properties are retained by so including the polyhydric alcohol and the polybasic carboxylic acid in the reaction mass. or batch, from which the resin is formed that I am able to obt in the desired sequence oi. reac-- tions without the addition or any solubilizins agent such as a resin, or a solubilizing acid such as monocarboxylic acid. prior to the reaction which involves the polybasic carboxylic acid.

The product resins thus retain hardness, gloss,

and thesaidhomogeneousj liolybaslc carboxylic acid with heating,

perature sumcienurmmgwsnve or interface" fuse the v polybasic carboxy'lic acid and sta iitlally above 1".,the propom nui uni additions to each other'and to, the ureaaldehyde' condensate lieingsuchthat the polyhyfdric aloo hol is in excess of the polyba'sic qarboxylic 'acid and such that each 0! thank in excess'o'f the condensate. and then with further temperature elevation makingat least one addition oifaeid selected from' the class consisting of the-aro- 1 w -mam acids and mixturesfof such acids.

2. ,lhe herein ducribed methodoi a modified urea-formaldehyde-resin by following the sequential steps of preparing a \llfl'gfbl'lll aldehyde condensate by reactingureaand 1 formaldehyde in the approximate proportion of 1 mol. of urea to 2mols. of formaldehyde at lowtemperature to a stage at which an opaque.

mass is formed. while themes-formaldehyde con? densate is still ung'elled forming a homogeneous mass 01' the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass witha polybasic carboxylic acid with heating to a" temperature sufficiently "high to drive of! waterand fuse'the polybasic car; boxylic acid and notsubstantially above 320 I".,

the proportions of the additions to each other and to theurea-i'ormaldehyde condensate being such that the polyhy'dric'alcohol is in excess of the polybaslc carboxyllc acid and such that each of them is in excess or the condensataand then with further temperature elevation making at least one addition of an acid selected from the class consisting of the aromatic monocarboxylic acids and mixtures of such acids.

3. The herein described method of producing a modified urea-aldehyde resin by following the sequential steps of preparing a urea-alde-' hyde condensate by reactingurea and aldehyde in the approximate proportion 01' 1- mol. of urea to 2-mols. of aldehyde at low temperature to astage at which an opaque resinous mass is formed, while the urea-aldehyde condensate is still ungelled forming a homogeneous-mass of the condensate with 'an unmodified polyhydric alcohol and reacting the said homogeneous mass with a ,polybasic carboxylic acid with heating to a temperature sumciently high to drive on water and fus the polybasiccarboxylic acid and not substantially above 320' R, the proportions of the additions to each other and to the urea-aldehydecondensate being such that the polyhydric a modified urea-aldehyde resin by following the sequential steps of preparing. a urea-aldehyde condensate by reacting urea and aldehyde in the approximate proportion of 1' mol. of urea "to 2V atwhichan opaque resinous mass is formed. while the urea-aldehyde condensate is still ungelled forming a' homogeneous mass of the-conmols. of aldehyde at low temperature to a stage alcohol is in excess of the poLvbasic carboxylic acid and such that each of them is in excess of the condensate, and then with further tempera ture elevation making at least one addition of benzoic acid. l

4. The herein described-method of producing -a modified urea formaldehyde resin by following the sequential steps of preparing a urea-form aldehyde condensate by reacting urea and formaldehyde in the approximate proportion ofl mol.

o! ur'eato 2 mols. of formaldehyde at low teinperature to a stage at which an opaque resinous mass is formed, while the urea-formaldehyde condensate'is still ungelled "forming a homogeneous mass of the condensate with an unmodiiled polyhydric alcohol and reacting the said homogeneous mass with a polybasic carboxylic acid with heating to a temperature suiliciently high to drive of! water and fuse the pobbasic carbowlic acid and not substantially above 320' F., the proportions of the additions to each other and to the urea-formaldehyde condensate being such that the polyhydrlc alcohol is in excess 01 the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of benaoic acid. I

5. The herein described method of producing a modified urea-aldehyde resin by following the sequential steps of preparing a urea-aldehyde condensate by reacting urea and aldehyde in the approximate proportion of'l mol. of urea to 2 mols. of aldehyde at'low temperature to a stage at which an opaque resinous mass is formed, while the urea-aldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass with a pohrbasic carboxylic acid with heating to a temperature sufflciently high to drive of! water and fuse the polybasic carbonlic acid and not substantially above 320 F., the proportions of the additions to each other and to the urea-aldehyde condensate being such that the polyhydric alcohol is in excess of the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of salicylic acid.

6. The herein described method of producing a modified urea-formaldehyde resin by following the sequential steps of. preparing a urea-formaldehyde condensate by reacting urea and formaldehyde in the approximate proportion of 1 mol. of urea to 2 mols. of formaldehyde at low temperature to a stage which an opaque resinous mass is formed, while the urea-formaldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass with a polybasic carboiwlic acid with heating to a temperature sumciently high to drive ofl water and fuse the poiybasic carboxylic acid and not substantially above 820 It, theproportionsoftheadditienstoeschother and to the urea-formalibhyde condensate being suchthatthepolyhydrioalcoholisinexcessof the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making ,at least one addition of salicylic acid.

7. The herein described method of producing a modified urea-aldehyde resin by following the sequential steps of preparing a urea-aldehyde condensateby reacting urea and aldehyde in the approximate proportion of 1 mol. of urea to 2 mole. of aldehyde at low temperature to a stage at which an opaque resinous mass is formed. while the urea-aldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified poly-hydric alcohol and reacting the said homogeneous mass with a poly-basic carboxylic acid with heating to a temperature sufilciently high to drive ofl water and fuse the polybasic carboxylic acid and not substantially above 320' E, the proportions of the additions to each other and to the urea-aldehyde condensate being such that the p lyhydric alcohol is in excess of the polybasic carbonlic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of anthranilic acid.

8. The herein described method of producing a modified urea-formaldehyde resin by following the sequential steps of preparing a urea-formaldehyde condensate by reacting urea and formaldehyde in the approximate proportion of 1 mol. of urea to 2 mols. of formaldehyde at low temperature to a stage at which an opaque resinous mass is formed, while the urea-formaldehyde condensate is still ungelled forming a homogeneous mass of. the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass witha polybasic carboxylic acid with heating to a temperature suiilciently high to drive oil water and fuse the polybasic carboxylic acid and not substantialb above 320' I'., the polybasic carboxylic acid and such'that each and to the urea-formaldehyde condensate being such that the polyhydric alcohol is in excess of the polybasic earboxylic acid and such that each ofthemisinexcessofthecondensateandthen with further temperature elevation making at least one addition of anthranilic acid.

SAMUEL 8. GUTKIN.

crann es-rs or comes-10s.-

Patuit llo. 2, 371 -311.-

-1 L et-5 SAMUEL 8. cums.

It is hereby certified that error appears in the above numbered patent requiring correction as follows; 'lhe specification and clains ot application Serial s 199,727, Patent. so. 2,57i 811 and application: Serial llo. 1985728, Patent No. 2, 3 7Ii,'812 were inadvertently transposed, therefore, in the heading to the pr'intedgpeeification 0am. patent, 112108, for "Serial so. 198,72?" read --Seria1 so. h9a,723'--;- and that a said letters Patent should be read with this correction therein that the same conform to the record of the ease in the Patent Office.

' Signed and sealed this 27th day of llovqaber A. n. 1915;

Leslie Frazer First Assistant Commissioner of Patents.

high to drive of! water and fuse the pobbasic carbowlic acid and not substantially above 320' F., the proportions of the additions to each other and to the urea-formaldehyde condensate being such that the polyhydrlc alcohol is in excess 01 the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of benaoic acid. I

5. The herein described method of producing a modified urea-aldehyde resin by following the sequential steps of preparing a urea-aldehyde condensate by reacting urea and aldehyde in the approximate proportion of'l mol. of urea to 2 mols. of aldehyde at'low temperature to a stage at which an opaque resinous mass is formed, while the urea-aldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass with a pohrbasic carboxylic acid with heating to a temperature sufflciently high to drive of! water and fuse the polybasic carbonlic acid and not substantially above 320 F., the proportions of the additions to each other and to the urea-aldehyde condensate being such that the polyhydric alcohol is in excess of the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of salicylic acid.

6. The herein described method of producing a modified urea-formaldehyde resin by following the sequential steps of. preparing a urea-formaldehyde condensate by reacting urea and formaldehyde in the approximate proportion of 1 mol. of urea to 2 mols. of formaldehyde at low temperature to a stage which an opaque resinous mass is formed, while the urea-formaldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass with a polybasic carboiwlic acid with heating to a temperature sumciently high to drive ofl water and fuse the poiybasic carboxylic acid and not substantially above 820 It, theproportionsoftheadditienstoeschother and to the urea-formalibhyde condensate being suchthatthepolyhydrioalcoholisinexcessof the polybasic carboxylic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making ,at least one addition of salicylic acid.

7. The herein described method of producing a modified urea-aldehyde resin by following the sequential steps of preparing a urea-aldehyde condensateby reacting urea and aldehyde in the approximate proportion of 1 mol. of urea to 2 mole. of aldehyde at low temperature to a stage at which an opaque resinous mass is formed. while the urea-aldehyde condensate is still ungelled forming a homogeneous mass of the condensate with an unmodified poly-hydric alcohol and reacting the said homogeneous mass with a poly-basic carboxylic acid with heating to a temperature sufilciently high to drive ofl water and fuse the polybasic carboxylic acid and not substantially above 320' E, the proportions of the additions to each other and to the urea-aldehyde condensate being such that the p lyhydric alcohol is in excess of the polybasic carbonlic acid and such that each of them is in excess of the condensate, and then with further temperature elevation making at least one addition of anthranilic acid.

8. The herein described method of producing a modified urea-formaldehyde resin by following the sequential steps of preparing a urea-formaldehyde condensate by reacting urea and formaldehyde in the approximate proportion of 1 mol. of urea to 2 mols. of formaldehyde at low temperature to a stage at which an opaque resinous mass is formed, while the urea-formaldehyde condensate is still ungelled forming a homogeneous mass of. the condensate with an unmodified polyhydric alcohol and reacting the said homogeneous mass witha polybasic carboxylic acid with heating to a temperature suiilciently high to drive oil water and fuse the polybasic carboxylic acid and not substantialb above 320' I'., the polybasic carboxylic acid and such'that each and to the urea-formaldehyde condensate being such that the polyhydric alcohol is in excess of the polybasic earboxylic acid and such that each ofthemisinexcessofthecondensateandthen with further temperature elevation making at least one addition of anthranilic acid.

SAMUEL 8. GUTKIN.

crann es-rs or comes-10s.-

Patuit llo. 2, 371 -311.-

-1 L et-5 SAMUEL 8. cums.

It is hereby certified that error appears in the above numbered patent requiring correction as follows; 'lhe specification and clains ot application Serial s 199,727, Patent. so. 2,57i 811 and application: Serial llo. 1985728, Patent No. 2, 3 7Ii,'812 were inadvertently transposed, therefore, in the heading to the pr'intedgpeeification 0am. patent, 112108, for "Serial so. 198,72?" read --Seria1 so. h9a,723'--;- and that a said letters Patent should be read with this correction therein that the same conform to the record of the ease in the Patent Office.

' Signed and sealed this 27th day of llovqaber A. n. 1915;

Leslie Frazer First Assistant Commissioner of Patents. 

